Stator winding apparatus with selectively movable coil former

ABSTRACT

A wound stator for a permanent magnet electric machine has an array of coils on the outer rim of a generally cylindrical stator body. The stator coils are wound directly on the stator body by providing the stator body with a plurality of mutually circumferentially-spaced, coil-retaining and forming members around which the ends of the stator coils are coursed so that the coil sides project in a direction parallel to the center axis of the stator. Wire connections are formed between coils of a phase, and wire loops are formed between the last wound coil of one phase and the first wound coil of a subsequently wound phase. Mechanisms are provided for clamping the stator start wires and for temporarily retaining the wire loops.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of application Ser. No. 08/017,111, filed Feb. 12,1993, now U.S. Pat. No. 5,394,046, which is a continuation-in-part ofapplication of Patrick A. Dolgas and Ballard E. Walton, Ser. No.07/950,262, filed Sep. 23, 1992, now abandoned which was acontinuation-in-part of application of Patrick A. Dolgas and Ballard E.Walton, Ser. No. 07/948,399, filed Sep. 21, 1992, now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to a stator and winding apparatus and, althoughnot necessarily so limited, more particularly to a stator windingapparatus for winding field coils wound on the outer, cylindrical rim ofa cylindrical stator core.

This invention was developed for use in winding field coils on statorsfor motors having internal stators of the type disclosed in U.S. Pat.No. 4,924,125. Such stators are used with surrounding rotors that rotateabout an axis coincident with the center axis of the stator. However,aspects of and this invention may be useful for winding other types ofelectric motor stators.

A key feature of stators of the type disclosed in said U.S. Pat. No.4,924,125 is that the sides of the stator coils are located on the outerrim surface of the body of the stator, in parallel relation to thecenter axis of the stator; there are no coil-receiving slots in thestator body itself. In order to manufacture stators of this type, thepractice has been to wind the coils separately from the stator body andthen to mount the coils onto the stator body, forming the coils asdesired to the contours of the stator body and then mounting them, as bytying them together, on the stator body. The processes used in the pastare cumbersome, time-consuming, and unduly expensive. Accordingly, thereis a need for an improved method and apparatus for manufacturing suchstators.

SUMMARY OF THE INVENTION

This invention provides an improved apparatus for winding stators havingan array of coils on the outer rim of a generally cylindrical statorbody. In accordance with this invention, the stator coils are wounddirectly on the stator body by providing the stator body with aplurality of mutually circumferentially-spaced, coil-retaining andforming members around which the ends of the stator coils are coursed sothat the coil sides project in a direction parallel to the center axisof the stator. An apparatus for forming connections between coils of aphase, for forming wire loops between the last wound coil of one phaseand the first wound coil of a subsequently wound phase, and for clampingthe start wires preparatory to the winding of a stator is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, partly exploded perspective view, with partsbroken away, of a portion of a winding machine and an unwound stator inaccordance with this invention.

FIG. 2 is a fragmentary side elevational view, with parts broken awayand in cross section, of the machine of FIG. 1 on a larger scale thanFIG. 1. FIG. 2 also shows the stator of this invention in phantom.

FIG. 3 is a fragmentary top plan view of a portion of the machine ofFIG. 1, including a center winding form from which a top plate has beenremoved to reveal details of construction, and also including a portionof a stator being wound.

FIG. 4 is a view similar to FIG. 3, but showing the center winding formwith its top plate in position and illustrating a later stage in thewinding of the stator than that illustrated in FIG. 3.

FIG. 5 is a fragmentary top plan view similar to FIGS. 3 and 4 butshowing a slightly different portion of the machine. FIG. 5 illustratesa still later stage in the winding of the stator.

FIG. 6 is a fragmentary perspective view, as viewed in the direction ofarrows 6--6 of FIG. 5, of a portion of the stator core and a coil woundthereon.

FIG. 7 is a view similar to FIG. 3 at still a later stage in the windingof the stator.

FIG. 8 is a cross sectional view taken along line 8--8 of FIG. 7 of aportion of the center winding form and a driver used with the centerwinding form.

FIG. 9 is an enlarged fragmentary cross section of the center windingform taken along line 9--9 of FIG. 8.

FIG. 10 is view similar to FIG. 9 but also shows a driver associatedtherewith.

FIG. 11 is a view similar to FIG. 7 at a still later stage in thewinding of the stator.

FIG. 12 is fragmentary top plan view of the stator diagrammaticallyillustrating the stator after it is fully wound.

FIG. 13 is a fragmentary, partly exploded perspective view, with partsbroken away, of a portion of a second embodiment of a winding machineand an unwound stator in accordance with this invention.

FIG. 14 is a fragmentary side elevational view, with parts broken awayand in cross section, of the machine of FIG. 13 on a larger scale thanFIG. 13. FIG. 14 also shows the stator of this invention in phantom.

FIG. 15 is a view similar to FIG. 4, illustrating a stage in the windingof a stator using the machine of the embodiment of FIGS. 13 and 14.

FIG. 16 is an exploded, partly diagrammatic, perspective view ofportions of a prior art electrical machine.

DETAILED DESCRIPTION

The present invention relates to the type of electrical machine, whichmay be a motor or an alternator, generally designated 20 in FIG. 16,having a cup-shaped rotor 22, with a center shaft 24 that is mounted bybearings 26 in the hub 28 for rotation of the rotor 22 about the centeraxis of a stator, generally designated 30. The stator 30 includes acylindrical core 32, which may be made from a glass filled resin, and aplurality of shallow, pole-forming coils 34 wound from magnet wire. Aplurality of permanent magnets 36 are mounted within the rotor 22 whichcooperate with the wound poles so that the machine 20, when assembled,will function as either a motor or as an alternator. This type ofelectrical machine is disclosed in the above-mentioned U.S. Pat. No.4,924,125.

With reference to FIG. 1, a stator core, generally designated 40, isillustrated which is based on the prior art device shown in FIG. 16 butmodified in accordance with this invention. The stator core 40 of thisinvention has a circular first end face 42 and a circular second endface 44. Referring also to FIG. 6, both end faces 42 and 44 have outermargins 46 spaced by and joined to a cylindrical outer wall 48.(Although not pertinent to the instant invention, the outer wall 48 hasa mild steel band (not shown) covered by a band of insulating material50 mounted over a glass-filled resin substrate.) As in the prior art,the end faces 42 and 44 are centered on a common axis which iscoincident with the center axis of the outer wall 48.

The stator core 40 is modified in accordance with this invention toinclude a first set of axially-outwardly projecting coil-retaining andforming members 52 mounted in mutually-spaced relation on the outermargin of its first end face 42, and to include a second set ofaxially-outwardly projecting coil-retaining and forming members 54mounted on the outer margin of its second end face 44. Individual onesof the coil-retaining and forming members 54 of the second set arealigned with individual ones of the coil-retaining and forming members52 of the first set. The coil-retaining and forming members 52 and 54project axially further outwardly from the end faces 42 and 44,respectively, than any of the coils wound on the stator core 40, as willbe described below. To help guide the wire segments forming the woundpoles, as will be discussed below, the coil-retaining and formingmembers 52 and 54 have inner faces, designated 56, which are their facesnearest the center axis of the stator core 40, which faces slope bothradially and axially outwardly from their associated end faces 42 and44. Referring to FIG. 6, the poles wound on the stator core 40 areformed from individual coils "C", each having sides "S" extendingaxially along the outer wall 48 in parallel relation to the center axisof the stator, and ends "E" extending over the first and second core endfaces 42 and 44. Corners of the coils "C" joining the sides "S" and theends "E" are formed around aligned pairs of the first and second sets ofcoil-retaining and forming members 52 and 54 and extend over the endfaces 42 and 44. In the particular embodiment illustrated in thedrawings, these aligned pairs of coil-retaining and forming members 52and 54 are located on opposite sides of intermediate coil-retaining andforming member 52 and 54 which are spanned by the coil "C".

As will be understood by reference first to FIGS. 5 and 6, and then toFIGS. 7 and 12, all of the coils that form a first phase, which coilsare designated numbers 60-1, 60-2, 60-3 . . . 60-10, are wound inseriatim on the stator core 40 in mutually equally-spaced relationaround the circumference of the stator core 40. This is followed by thewinding in seriatim of equally-spaced second phase coils, designated62-1, 62-2, 62-3 . . . 62-10, and then by the winding in seriatim ofequally-spaced third phase coils, designated 64-1, 64-2, 64-3 . . .64-10. (Aspects of this invention may be applicable to stators havingother than three phase windings, but this invention will most often beapplied to three phase stators.)

With reference to FIGS. 1 and 2, a stator winding machine in accordancewith this invention is generally designated 70 and includes a suitableframe 72 on which a stator core indexing apparatus 74 driven by suitabledrive motor 75 is mounted. The indexing apparatus 74 includes a supportblock 76 and an upwardly extending spindle 78 to locate the stator cores40 in position to be wound, which is the position illustrated by thestator core 40 shown in phantom lines in FIG. 2. A stator core to bewound is clamped to the indexing apparatus 74 in any suitable fashion,as by the illustrated clamp rod 80 which extends upwardly through theindexer spindle 78 and is operated by an air actuator 82. As isapparent, the clamp rod 80 carries a lower camming member 84 thatpresses upwardly on pivotal clamping plates 86 to lock a stator 40 tothe spindle 78 and an upper camming member 88 that moves downwardly topivot the clamping plates 86 to a position to permit removal of a woundstator and replacement by an unwound stator core. Lower camming member84 is mounted on a bearing 87 so that it may rotate with the statorbeing wound when it is indexed as will be described below. Upper cammingmember 88 may be affixed, as by mutually cooperating threads, to theupper end of the clamp rod 80 and held non-rotatably thereto a hexagonalstop nut 89. The indexing apparatus 74 is only diagrammaticallyillustrated in the drawings. An example of an indexing apparatussuitable for the purposes of this invention is known as a Model EXFD200Electrodex, which is available from Ferguson Machine Company, 11820Lackland Road, St. Louis, Mo. 63146.

Coils are wound on a stator core 40 mounted on the indexing apparatus74, in what may be referred to as a "winding station", by means of arotating wire-guiding flier 90 that is connected to a rotatable flierspindle 92 which is mounted for rotation by bearings 93 on a pair ofspindle support plates 94 and 96 mounted vertically on a horizontalcarriage 98 which is mounted for movement along guide tracks 100 on themachine frame 72 for movement toward and away from the winding stationby operation of a carriage drive air actuator 102. The flier spindle 92is driven by a suitable motor 104 mounted on the spindle support plate96. The flier 90 includes a wire exit pulley 106 from which wire exitsfrom a wire guide tube 108 in the flier spindle 92, a flier arm 110 thatextends outwardly from the flier spindle 92, and a flier guide pulley112 at the end of the flier arm 110 which, upon rotation of the flier90, causes insulated magnet wire W through the flier spindle 92 to bewound into coils "C". The flier arm 110 and the pulley 112 are balancedby a counterbalancing arm 114 and weight 116. During rotation of theflier 90, as is well known, the wire W is drawn from a source (notshown) of wire under tension. As is conventional with flier-typewinders, at the beginning of the winding of a stator, the wire exitingfrom the flier, which has been cut free from the previously woundstator, is gripped by a suitable clamp (not shown).

In order to form the wires into the coils "C", a winding form assembly,generally designated 120, is mounted by bearings 122 and 123 on the endof the flier spindle 92 nearest the winding station. Winding formassembly 120 comprises a generally rectangular, central body 125 onwhich is mounted an upper wire guide plate 124 and a lower wire guideplate 126, both of which have beak-like, arcuately convex, wire guideportions 128 that extend, respectively, above and below the end faces ofa stator core 40 in the winding station.

With reference to FIGS. 1, 2, 3, 7 and 8, the winding form assembly 120further includes two pairs of movable coil formers, namely a pair ofupper and lower tight side coil formers 130 (as viewed in FIGS. 1, 3, 7and 8) and a pair of upper and lower left side coil formers 132. Withreference to FIG. 3, the two pairs of coil formers 130 and 132 areextended over a stator core 40 at the winding station during the windingof the coils 60 of the first phase. When in this position, the coilformers 130 and 132 cooperate, respectively, with the upper and lowerwire guide plates 124 and 126 to cause the wire W to wrap around upperand lower pairs of the coil-retaining and forming members 52 and 54fixed to the end faces 42 and 44 of the stator 40 and also around theupper and lower pairs of movable coil formers 130 and 132. The movablecoil formers are so extended over the stator core end faces 42 and 44that the coil ends "E" are formed thereby further toward the center axisof the stator core 40 than would be the case if the movable coil formers130 and 132 were retracted. As will be seen, this provides space for thewinding of coils of subsequent phases.

With reference to FIG. 7, one side of each second phase coil 62 overlapsone side of a first phase coil 60. To avoid interference between theleft side coil formers 132 and the first phase coils 60, the left sidecoil formers 132 are retracted when winding coils 62 of the secondphase. The right side coil formers 130 remain extended so that theportion of the second phase coil end which does not overlap a firstphase coil is formed by the same distance toward the center axis as theends of the first phase coils. As shown in FIG. 11, each coil 64 of thethird phase overlaps one first phase coil 60 and one coil 62 of thesecond phase, the portion of the second phase coil 62 being overlappedbeing that portion whose end is formed toward the center axis of thestator core 40 by the right side coil former 130 and shown in FIG. 7. Asis evident, both pairs of coil formers 130 and 132 must be retracted inpreparation for the winding of the third phase coils 64 to avoidinterference with the previously wound coils.

Referring to FIGS. 1, 2, 4 and 8 through 10, extension and retraction ofthe right side coil former 130 is accomplished by a drive mechanismcomprising a pair of racks 134 and 136 connected, respectively, to theupper and lower formers 130, and engaged by a vertical pinion driveshaft 138 mounted by bearings in the upper 14 and lower guide plates 124and 126. A pinion drive actuator assembly 140 is mounted on the carriage98 above the winding form assembly 120. The pinion drive actuatorassembly 140 includes a vertically oriented air actuator 142 mounted forrotation on a pair of horizontal support plates 144 and 146. Actuator142 has a nonrotating piston (not shown) and may be of the type known asFesto Model DZH which is available from Festo Corporation, 395 MorelandRoad, Hauppauge, N.Y. 11788. The depending end of its piston rod,designated 148, has a drive key 150 adapted to enter a slot 152 in thetop of the pinion drive shaft 138 upon actuation of the actuator 142.Upon entry of the key 150 into the slot 152, a locking dog 154, whichnormally fits into a locking groove 156 in the winding form upper plate124 to prevent retraction of the right side movable coil former 130, ispivoted out of the locking groove 156 to release the pinion drive shaft138 for rotation. At this time, a rotary air actuator 158 affixed to thetop of the upper support plate 146 and drivingly connected to the airactuator 142 is energized to rotate the pinion drive shaft 138 andthereby retract the movable right side coil formers 130. Later on, whenthe piston rod 148 is retracted to permit the subsequent winding ofcoils, the locking dog 154, which is biased by a spring-loaded pin 160,frictionally bears against surfaces of the upper wire guide plate 124 toovercome any tendency that the drive pinion 138 may have to rotate toextend the movable coil formers 130. It will be apparent by now that thekey 150 can be lowered again into the slot 152 and the operation of therotary actuator reversed to extend the coil formers 130 for the windingof the next stator.

The extension and retraction of the left side movable coil formers 132is accomplished by a duplicate mechanism for which like parts are givenlike reference numbers.

In the operation of the stator winder 70, the winding form assembly 120is retracted away from the winding station to enable removal of a woundstator and replacement by an unwound stator core 40. The orientation ofthe winding form assembly is maintained at this time by a winding formbrake member 164 (FIG. 2) driven downwardly into engagement with the topsurface of the winding form assembly by an air actuator 166. (The brakemember 164, is applied whenever the winding form assembly is retracted.Otherwise, the winding form assembly could rotate out of its properorientation since it is rotatably mounted with respect to the flierspindle 92.) After an unwound core is clamped to the indexing apparatus74, the winding form assembly 120 is advanced, by operation of thecarriage drive cylinder 102, to move the winding form assembly 120 intoposition for winding the first coil 60-1 of the first phase. At thistime, rotation of the winding form assembly 120 is prevented by theengagement of a pair of stabilizing plates 168 (FIG. 2) with the top andbottom surfaces, respectively, of the three pairs of uppermost andlowermost wire-retaining and forming members 52 and 54 straddled by theupper and lower wire guide plates 124 and 126, and the brake member 164is retracted by operation of its air actuator 166. The stabilizingplates 168 are preferably spring biased and guided by pins 167 thatextend through slots 169 in the upper and lower wire guide plates,respectively, so that they will assuredly engage the stator core 40without damaging it. At this time, the movable coil formers 130 and 132are extended as shown in FIG. 3 and, following retraction of the piniondrive actuators 138, the flier 90 is then rotated by rotation of itsspindle 92 to wind the coil 60-1.

With reference to FIGS. 2 and 3, it can be seen that, during the windingof the first coil 60-1, as the flier 90 rotates to cause the wire W tomove over the coil-forming wire guide portions 128 of the winding formassembly 120, the wire is forced thereby to extend a substantialdistance closer to the center axis of the stator core 40 than the innerfaces 56 of the coil-retaining and forming members 52 and 54. As theflier 90 continues to rotate, drawing the wire W off the wire guideportion 128, the wire W tends to snap outwardly toward and against thesurfaces of the movable coil formers 130 and 132 that face generallytoward the center axis of the stator core so that the coil 60-1 istightly and securely wound in the position illustrated in the drawings.

During the winding operation, the wire W is prevented from hooking overany of the adjacent coil-retaining and forming members 52 and 54 by apair of shield members 172 and 174 located, respectively, on oppositesides of the winding form assembly 120 and closely adjacent to thestator core 40 being wound. The shields 172 and 174 also insure that thewire W is directed against the winding form at all times when the flier90 is rotating.

After the winding of the coil 60-1, the flier 90 is stoppedapproximately in the position shown in FIG. 1 in preparation for theretraction of the carriage 98 to permit the stator 40 to be indexed.Prior to retraction of the carriage 98, a pivotal wire-guiding hook orpin 176 is pivoted by operation of an associated air actuator 178 intothe position shown in FIG. 4, where it holds the wire leading from thecoil 60-1 to the flier 90 generally over the stator core 40 and preventsthe wire from moving between the stator core 40 and the winding formassembly 120 when the carriage 98 is retracted, which could interferewith the subsequent operation of the machine.

The winding form 120 can now be retracted and the stator 40 indexed byoperation of the indexing apparatus 74 whereupon the parts reach theposition thereof illustrated in FIG. 4. The foregoing operations arerepeated until all of the coils 60 of the first phase have been wound.Referring to FIG. 5, it will be noted that the connecting wires betweenthe first phase coils 60 extend over the end face 42 which is uppermostin FIG. 5, where they are safe from damage.

After the completion of the first phase coils, and before the retractionof the carriage 98 to permit the next indexing movement of the statorcore 40, a lead wire loop 180, shown in FIG. 5, is preferably formedover the top of the stator end face 42. This is accomplished by means ofa looping assembly, generally designated 181 in FIGS. 1, 2 and 5, andcomprising an L-shaped looping pin 182 mounted on a vertical supportshaft 184 driven by a rack 186 which in turn is driven by a compound airactuator 188. The upper end of the support shaft 184 is coupled to thepiston rod 190 of an air actuator 192 by which the support shaft 184,and accordingly the looping pin 182, can be raised and lowered.

In operation, at the end of the winding of the last coil of the firstphase, the looping pin 182, which is in its raised position, is pivotedby operation of the rack 186 to the position shown in full lines in FIG.5 against or nearly against a stop plate 194 in the top of the left sideshield 174. The looping pin 182 is then lowered so that its vertical legis positioned to engage the segment of wire W leading from the last coilof the first phase to the flier 90. The looping pin 182 is then pivotedback to the position thereof indicated by phantom lines 196 so as todraw a loop 180 in the wire. After the loop 180 is drawn, the carriage98 is retracted and the stator indexed as before, but through a lesserangle, to reposition the stator core 40 for receiving the first coil62-1 of the second phase. (In the illustrated embodiment, the index fromthe end of one phase to the beginning of the next is through 12 degreesas shown in FIG. 12.) During the indexing of the stator core 40 at thistime, the wire loop 180 is held against the vertical leg of the loopingpin 182 by operation of a conventional dancer arm or other wire take-updevice (not shown) associated with the source of wire under tension.When the stator core 40 is next indexed after the winding of the firstphase two coil 62-1, the wire loop 180 moves away from the vertical legof the looping pin 182, which can then be raised out of the way andreturned to its home position, shown by phantom lines 198 in FIG. 5,where it will not interfere with the removal of the wound stator.

Those familiar with the art will readily understand that the foregoingoperations are repeated as necessary to complete the winding of thestator, at which time it is removed and replaced by an unwound stator.

It will be noted that, using the apparatus of this invention, theentirety of the ends of all of the coils of all three phase coils arelocated over the stator end faces 42 and 44 and closer to theirassociated faces 42 and 44 than are the outer extremities of thecoil-retaining and forming members 52 and 54.

FIGS. 13, 14 and 15 illustrate a second embodiment of a winding machine,generally designated 200, in accordance with this invention used to winda stator, generally designated 202. The same reference numbers are usedin these figures for parts of the machine 200 and the stator 202 thatare essentially the same as corresponding parts of the machine 70 andthe stator 40 of FIGS. 1 through 12, and such parts are not furtherdescribed herein.

The machine 200 differs from the machine 70 in that the machine 200includes a wire clamp and loop holder assembly, generally designated204, and further includes a wire positioning assembly, generallydesignated 206. In the machine 200 of the second embodiment, the wireloop forming function provided by the wire clamp and loop holderassembly 204 is performed manually or with the use of suitable tools, aswill be further described below. Therefore, the wire looping assembly181 of the machine 70 of the first embodiment is not used in the machine200. The wire positioning assembly 206 is used in lieu of the wire guidepin 176 and its air actuator 178. Except as described above, the machine200 may be identical in construction and, except as described below, inoperation to the machine 70 of the first embodiment.

Wire clamp and loop holder assembly 204 is mounted on the upper end ofthe stator clamp rod 80 and includes a clamp washer 208 freely rotatablymounted on the clamp rod 80 and supported on top of the stop nut 89, andfurther includes a clamp member 212 threaded onto the top end of theclamp rod 80 so that it would, when rotated, be moved toward and awayfrom the clamp washer 208. In use, the operator of the machine 200 can,after mounting an unwound stator core in the winding station, grasp thefree end of the wire segment extending from the flier 90, place itbetween the clamp washer 208 and the clamp nut 212, and clamp down onthe wire segment by rotating the clamp nut 212 to move it toward theclamp washer 208. This clamped wire segment is the start wire for thestator. Thus, it leads into the first coil to be wound. If the wiresegment is looped in the appropriate direction around the shaft 80before it is clamped between the clamp washer 208 and the clamp nut 212,that wire segment will simply unwind from the shaft 80 during thewinding of the coils of the first phase. At any time thereafter, theoperator may release the free end of the clamped wire segment byreversely rotating the clamp nut 212. In practice, this can convenientlybe done immediately after the coils of the first phase are wound.

To provide a wire loop holding function, i.e. to temporarily hold abetween-phase wire loop, such as the wire loop 180 described above, avertically-extending groove 214 is formed along the outer edge of clampnut 212 in a position so located that the groove 214 faces away from theflier 90 when the clamp nut 212 is tightened against the clamp washer208--a position which is 90 degrees to the left of the positionillustrated in FIG. 14. In use, after the first phase coils are woundand the stator lead wire unclamped, the operator can grasp the wiresegment between the flier 90 and the last-wound coil, pull it to form aloop of wire, either by hand or with a suitable hook-like tool (notshown), and place the bight of the wire loop into the groove 214. Thestator 202 can then be indexed to enable the winding of the coils of thesecond phase. Because the clamp nut 212 does not rotate as the stator isindexed, the loop is moved out of the groove 214 during the winding ofthe second-phase coils and simply overlies the stator 202, out of theway of the flier 90. A loop can similarly be formed between thesecond-phase coils and the third-phase coils and temporarily engaged in,and then removed from, the clamp nut 212 in the same way as the wireloop between the first and second phases.

The wire positioning assembly 206 comprises a pair of wire-guiding pinsor hooks, namely an upper hook 220 and a lower hook 222, connected tothe upper and lower ends of a vertical drive shaft 224 rotatable invertically-spaced bearing blocks 226 supported by a bracket 228. Ahook-operating air actuator 230, which is preferably (andconventionally) mounted in any suitable fashion for limited pivotalmovement is adapted to drive a rack 232 engaged with a splined centersection 234 of the drive shaft 224. In operation, both hooks 220 and 222are pivoted so that their free ends are within the orbit of the flier 90after the winding of each coil and then pivoted to a position remotefrom the winding area after the stator is repositioned before the flierbegins to rotate to wind the next coil.

The machine 200 has two pins or hooks 220 and 222, instead of the singlewire positioning pin 176 of the first embodiment, to accommodate forcircumstances in which the stator is so wound that the flier stops belowas well as above the stator. With reference to FIG. 15, the stator 202is wound by a procedure in which the first coil, designated 236-1, ofthe first phase is wound in one direction and the stator is then indexedthrough only one-half of angle through which the stator 40 is indexed inthe first embodiment described above. The second coil, designated 236-2,of the first phase is then wound with one of its sides locatedside-by-side in abutment with a side of the first- wound coil 236-1. Thesecond coil 236-2 is wound in the opposite direction to the first coilso that the abutting sides of the two coils run electrically in the samedirection. This opposite direction of rotation for alternate coils iscontinued throughout the winding of the stator. Accordingly, the flier90 will stop above the stator 40 after the winding of half of the coils,i.e. those formed by rotation of the flier in one direction, and belowthe stator after the winding of the other half of the coils, i.e. forthe alternate coils formed by rotation of the flier 90 in the oppositedirection.

With continued reference to FIGS. 13, 14 and 15, the pins or hooks 220and 222 are each provided with a cam plate 225, the purpose of which isto cam the wire segments engaged by the wire hooks 220 and 222 towardtheir free ends. When positioned within the orbit of rotation of theflier 90, the free ends of the hooks 220 and 222 are so located that thewire segments engaged thereby are in substantial vertical alignment withthe coil side of the last coil from which the wire lead extends, butwith the portion of the wire engaged by the hook 220 or 222, as the casemay be, held radially closer to the center of the stator so that thestator can be indexed without concern that the wire lead will cross overinto the area of the next coil to be wound. (In FIG. 15, the stator 202has been indexed to locate it in position for the winding of the thirdcoil of the first phase, so that the coil side from which the last wirelead, designated 238, extends has been indexed away from the position itoccupied below the free end of the hook 220 at the end of the winding ofthe coil 236-2.)

As is evident, one of the hooks 220 or 222 will not engage a wiresegment when the other of the hooks 220 or 222 is engaged with a wiresegment, so that it would not be necessary to pivot both hooks 220 and222 at the same time. It will also be evident that there may be cases inwhich only one of the hooks 220 or 222 is used to engage the wiresegments leading from the coils. This will depend upon the windingpattern for the particular stator being wound.

The embodiment of FIGS. 1 through 12 is preferred for automaticproduction of stators, but may advantageously be modified to include thewire positioning assembly of FIGS. 13, 14 and 15. The second embodimentshown in FIGS. 13, 14 and 15, is useful and may in some cases bepreferred for low production, laboratory, or repair purposes.

Although the presently preferred embodiment of this invention has beendescribed, it will be understood that within the purview of theinvention various changes may be made within the scope of the followingclaims.

We claim:
 1. An apparatus for winding a stator core for a permanentmagnet motor, said stator core having first and second end faces eachhaving outer margins spaced by and joined to a cylindrical outer wallhaving a center axis, a first set of axially-outwardly projectingcoil-retaining members in mutually-spaced relation on the outer marginof said first end face, and a second set of axially-outwardly projectingcoil-retaining members on the outer margin of said second end face,individual ones of said coil-retaining members of said second set beingaligned with individual ones of said coil-retaining members of saidfirst set, said apparatus comprising:an indexing mechanism to which saidstator core is adapted to be clamped; a carriage movable between a firstposition remote from said stator core and a second position adjacentsaid stator core; a rotatable flier mounted on said carriage, said flierdrawing wire from a source of wire under tension and rotatable when saidcarriage is moved to said second position to wind coils of wire aroundindividual pairs of said first set of said coil-retaining members andaligned pairs of said second set of coil-retaining members; and awinding form assembly mounted on said carriage including a first coilformer selectively movable between a first position remote from saidstator core and a second position over and confronting one of said endfaces of said stator core, said first coil former when in said secondposition having surfaces located in the path of said wire being wound sothat a portion of one of said coils of wire extending over said one ofsaid end faces is wound closer to said center axis than if said firstcoil former were in said first position.
 2. The apparatus of claim 1wherein said winding form assembly further includes a second coil formerselectively movable between a first position remote from said statorcore and a second position over and confronting one of said end faces ofsaid stator core, said second coil former when in said second positionhaving surfaces located in the path of said wire being wound so thatanother portion of said one of said coils of wire extending over one ofsaid end faces is wound closer to said center axis than if said secondcoil former were in said first position.
 3. The apparatus of claim 2wherein said first coil former and said second coil former are over andconfronting the same one of said end faces when in their respectivesecond positions.
 4. The apparatus of claim 3 wherein said portion ofsaid one of said coils wound closer to said center axis when said firstcoil former is in said second position is adjacent said portion of saidone of said coils wound closer to said center axis when said second coilformer is in said second position.
 5. The apparatus of claim 3 whereinboth said portion of said one of said coils wound closer to said centeraxis when said first coil former is in said second position and saidportion of one of said coils wound closer to said center axis when saidsecond coil former is in said second position are wound the samedistance closer to said center axis.
 6. The apparatus of claim 2 whereinsaid first coil former is over and confronting said first end face whenin said second position and said second coil former is over andconfronting said second end face when in said second position.
 7. Theapparatus of claim 6 wherein both said portion of said one of said coilswound closer to said center axis when said first coil former is in saidsecond position and said portion of one of said coils wound closer tosaid center axis when said second coil former is in said second positionare wound the same distance closer to said center axis.
 8. The apparatusof claim 1 further comprising a clamp assembly for clamping a start wirefor the first coil wound adjacent the stator core while at least some ofthe coils are being wound.
 9. The apparatus of claim 1 furthercomprising mechanism for forming a loop in said wire between one of saidcoils of wire and another of said coils of wire.
 10. An apparatus forwinding a stator core for a permanent magnet motor, said stator corehaving first and second end faces each having outer margins spaced byand joined to a cylindrical outer wall having a center axis, a first setof axially-outwardly projecting coil-retaining members inmutually-spaced relation on the outer margin of said first end face, anda second set of axially-outwardly projecting coil-retaining members onthe outer margin of said second end face, individual ones of saidcoil-retaining members of said second set being aligned with individualones of said coil-retaining members of said first set, said apparatuscomprising:an indexing mechanism to which said stator core is adapted tobe clamped, said indexing mechanism including a clamp rod; a carriagemovable between a first position remote from said stator core and asecond position adjacent said stator core; a rotatable flier mounted onsaid carriage, said flier drawing wire from a source of wire undertension and rotatable when said carriage is moved to said secondposition to wind coils of wire around individual pairs of said first setof said coil-retaining members and aligned pairs of said second set ofcoil-retaining members; and a mechanism for forming a loop in said wirebetween one of said coils of wire and another of said coils of wire,said looping mechanism comprising a wire clamp and loop holder assemblycomprising a clamp washer freely mounted on said clamp rod and a clampnut threadedly mounted to said clamp rod and rotatably movable towardand away from said clamp washer, said clamp nut having avertically-extending groove formed along the outer edge thereof foraccepting the bight of a wire loop in the wire used to form said coilsof wire.
 11. The apparatus of claim 10 wherein said clamp nut isadjustable to clamp a portion of said wire used to form said coils ofwire between said clamp nut and said washer when said clamp nut istightened against said clamp washer.
 12. The apparatus of claim 11wherein said groove faces away from said flier when said nut istightened against said washer.
 13. An apparatus for winding a statorcore for a permanent magnet motor, said stator core having first andsecond end faces each having outer margins spaced by and joined to acylindrical outer wall having a center axis, a first set ofaxially-outwardly projecting coil-retaining members in mutually-spacedrelation on the outer margin of said first end face, and a second set ofaxially-outwardly projecting coil-retaining members on the outer marginof said second end face, individual ones of said coil-retaining membersof said second set being aligned with individual ones of saidcoil-retaining members of said first set, said apparatus comprising:anindexing mechanism to which said stator core is adapted to be clamped,said indexing mechanism including a clamp rod; a carriage movablebetween a first position remote from said stator core and a secondposition adjacent said stator core; a rotatable flier mounted on saidcarriage, said flier drawing wire from a source of wire under tensionand rotatable when said carriage is moved to said second position towind coils of wire around individual pairs of said first set of saidcoil-retaining members and aligned pairs of said second set ofcoil-retaining members; a winding form assembly mounted on said carriageincluding a first coil former selectively movable between a firstposition remote from said stator core and a second position over one ofsaid end faces of said stator core, said first coil former when in saidsecond position having surfaces located in the path of said wire beingwound so that a portion of one of said coils of wire extending over saidone of said end faces is wound closer to said center axis than if saidfirst coil former were in said first position; and a mechanism forforming a loop in said wire between one of said coils of wire andanother of said coils of wire, said looping mechanism comprising a wireclamp and loop holder assembly comprising a clamp washer freely mountedon said clamp rod and a clamp nut threadedly mounted to said clamp rodand rotatably movable toward and away from said clamp washer.